Many people think that the lower the pump head, the smaller the motor load. Misguided by this misunderstanding, when purchasing pumps, the pump head is often chosen very high. In fact, for centrifugal pumps, when the model of the pump is determined, the power consumption is directly proportional to the actual flow of the pump. The flow of water pump will decrease with the increase of lift, so the higher the lift, the smaller the flow and the smaller the power consumption. Conversely, the lower the lift, the greater the flow and the greater the power consumed.
Therefore, in order to prevent the motor from being overloaded, it is generally required that the actual pumping lift of the pump is not less than 60% of the rated lift. Therefore, pumping water with high lift, the lift is too low, the motor is easy to overload and heat up, and it will burn out the motor in serious cases. In case of emergency, a gate valve must be installed on the outlet pipe to adjust the water output (or block the outlet with wood, etc.). ) reduce the flow to prevent motor overload. Pay attention to the temperature rise of motor. If the motor is found to be overheated, turn down the water flow or turn it off in time. This is also easy to misunderstand. Some drivers think that blocking the water outlet and forcibly reducing the flow will increase the motor load. In fact, on the contrary, the outlet pipe of the regular high-power centrifugal pump irrigation and drainage unit is equipped with gate valves. In order to reduce the motor load when the unit is started, the gate valve should be closed first and then gradually opened after the motor is started.
Large-caliber water pump with small water pipe for pumping water.
Many users think that this can improve the actual lift, in fact, the actual lift of the pump = total lift-loss lift. After the pump model is determined, the total lift is certain;
The loss of lift mainly comes from pipeline resistance. The smaller the pipe diameter, the greater the resistance, so the greater the lift loss. Therefore, after reducing the pipe diameter, the actual lift of the pump will not increase, but will decrease, resulting in a decline in pump efficiency.
Similarly, a small-caliber pump pumping water with a large water pipe will not reduce the actual lift of the pump, but will reduce the loss lift because of the reduction of pipeline resistance, so that the actual lift will be improved. Some users think that the motor load will be greatly increased when small-caliber pumps use large water pipes to pump water. They think that after the pipe diameter increases, the water in the outlet pipe will exert great pressure on the pump impeller, which will greatly increase the motor load.
As we all know, the liquid pressure is only related to the lift force, and has nothing to do with the cross-sectional area of the water pipe. As long as the head is constant and the size of the pump impeller is constant, the pressure acting on the impeller is certain no matter how big the pipe diameter is. Only when the pipe diameter increases, the flow resistance will decrease, thus increasing the flow and power consumption.
But as long as it is within the rated lift range, the pump can work normally no matter how the pipe diameter increases, which can reduce the pipeline loss and improve the pump efficiency.
When installing the water inlet pipeline, the horizontal section is horizontal or upturned.
Doing so will make air gather in the water inlet pipe, reduce the vacuum degree of water pipes and pumps, reduce the suction head of pumps, and reduce the water output.
The correct way is: its horizontal section should be slightly inclined to the direction of water source, not horizontal or upward.
There are many elbows on the water inlet pipe.
If many elbows are used in the inlet pipe, the local water flow resistance will be increased. Moreover, the elbow should be turned vertically, not horizontally, so as to avoid gas accumulation.
The water inlet of the water pump is directly connected with the elbow.
This will make the water flow unevenly distributed when it enters the impeller through the elbow. When the diameter of the water inlet pipe is larger than the water inlet of the pump, an eccentric reducer should be installed. The flat part of the eccentric reducer should be mounted on it, and the inclined part should be mounted on it. Otherwise, air will gather, the water output will be reduced or the water can't be pumped, and the machine will crash. If the diameter of the water inlet pipe is equal to the inlet diameter of the water pump, a straight pipe should be added between the inlet of the water pump and the elbow, and the length of the straight pipe should not be less than 2 ~ 3 times the diameter of the water pipe.
The bottom of intake pipe with bottom valve is not vertical.
If installed in this way, the valve will not close automatically, resulting in water leakage. The correct installation method is: the bottom section of the water inlet pipe with bottom valve is preferably vertical. When vertical installation is not possible due to topographical conditions, the included angle between the water pipe axis and the horizontal plane should be above 60.
The water inlet of the water inlet pipe is in the wrong position.
1) The distance between the water inlet of the water inlet pipe and the bottom and wall of the water inlet tank is smaller than the diameter of the water inlet. If there is dirt such as sediment at the bottom of the pool, if the distance between the water inlet and the bottom of the pool is less than 1.5 times the diameter, it will lead to poor water intake or suction of sediment and sundries during pumping, which will block the water inlet.
2) When the inlet of the inlet pipe is not deep enough, it will cause a vortex on the water surface around the inlet pipe, which will affect the water inflow and reduce the water output. The correct installation method is: the water depth of small and medium-sized pumps is not less than 300 ~ 600 mm, and the water depth of large pumps is not less than 600 ~1000 mm.
The inlet of the inlet pipe is higher than the normal water level of the outlet tank.
If the outlet is higher than the normal water level of the outlet pool, the pump head will increase, but the flow will decrease. If the water outlet must be higher than the water level of the outlet pool due to topographic conditions, elbows and short pipes should be installed at the nozzle to siphon the water pipe and reduce the height of the outlet.
Inquire more about the winning performance, integrity information and qualification conditions of construction enterprises, and download the Jianjitong app for one-click inquiry;
(Download the link of Jianjitong APP:/#/? source=bdzd